Fossil mammals and mammals in general, belong to the subphylum of vertebrates. Every mammal, from mice to elephants and bats to whales, belongs to this group. The oldest known mammals date from the Triassic. But only after the extinction of the dinosaurs at the end of the Cretaceousperiod, could mammals take up a dominant position on our planet.

The first marine mammals appeared during the Eocene (part of the Paleogene era). Most famous are the bones of large ice age mammals like the woolly mammoth (Mammuthus primigenius) from the Pleistocene era. The bones of mammals are usually found disarticulated. Every bone has a Latin name: